Automatic train control system



Feb. 10. 1925. 1,526,084

v J. N. PAUL AUTQMATIC TRAIN CONTROL SYSTEM Uriginai Filed Nov. 20. -1919 I Fncal.

ack

mum Hunky, T I

Patented so, sees.

tel FT fi JGSEPE N. PAUL, OF RtJCHESTER, NEW YORK, ASSIGNO'R TO GENERAL BAILWAY SIGNAL COMPANY, OF ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK.

AUTOMATIC TBAIN GONTROL SYSTEM.

Application filed November 20, 1919, Serial No. 339,398. Renewed December 30, 19%.

particularly to the means employed in such systems for transmitting controlling impulses or influences from the trackway to locomotives, motorcars, or other railway vehicles moving thereon.

On account of exposure toweathcr, the

problems of clearance, and other reasons,

' track and parts on the moving vehicles.

"iron yokes or cores 'galong the, track.

it is desirable that the impulse transmitting means for train control systems should opcrate inductively, tl'iat is, without any physical contact between parts along the In one type of such an inductive system, and the type to which my present invention more particularly relates, the cautionary or stopping impulse is due to the presence of Other masses of iron, such as the track rails at crossings, crossovers and the like, have the. tendency to produce the same stopping effect, and if the equipment on the vehicle is too sensitive, improper operation will be produced by such masses of iron. On ths other hand, variations in airga-p between the car-carried element and the track element, which are bound to occur in practice, changes in the voltage of the battery on the car (wl'iic-h. is usually a storage battery), and other variable factoisin-pose in prac tice a. working limit to the sensitiveness of the car equipment, in. order that the safe and reliable operation may be obtained. Thus, if the equipment is designed and/adjust ce for safe and reliable operation under the worst conditions of air-gap, battery,

voltage'and the like, it isfound that the car equipment may he so sensitive as to; he sometimes improperly operated at crosslugs and thelike, when the. Les; conditions o-f-airgap, battery voltage, etc, exist. Adjustments for the airgap, battery voltage, and the like may be provided, if desired, to take care of this condition; but 1 con. sider it undesirable to depend upon; such adj ustmcnlsfisi nce the aquisite adjustment necessary to make the system safe may not be made sometime for some reason or another. I

In view of these considerations, one of the principal objects of my present invention is to provide an improved car equipment which willbe influenced to a verysmall degree by track rails at crossings, and like magnetic bodies along the track, without being any less sensitive to the efiect of a regular track element, so that the car equipment may be designed and adjusted so as to operate safely and reliably through the entire range of variations in airgap, battery voltage, or the like, without being susceptible to improper and false operations by the track rails at crossings and the like, I

"cuits. embodying the invention;

Fig. 2 illustrates in a diagran'imatic and simplified manner the construction and arrangement of the parts and circuits consti toting. the car'equipnicnt, together with the track element forming part of the track equipment; and

Fig. 3 illustrates amodified arrangement of the car equipment.

Referring first to the track equipment shown in Fig. 1, my invention includes track elements T which are auton'iatically governed in accordance with traffic conditions. Various arrangements of trackway circuits for governing these track elements 1 ,maybe employed; audit should be understood that the circuits illustrated in Fig. 1 are merely typical, Thetrack rails l of the railroad track are divided by insulated joints 2 into blocks in the usual way, one

block I with the adjacent ends of two other blocksl-l and J, being shown. The parts and c rou'lts associated with the various blocks are the same, and for convenience mosses will be given like reference characters, with ineuts may be employed Without departing distinctive exponents, Each of the blocks is provided with a ti'rlck battery 3 and a track relay i, the some in ordinary block signel systems? My invention may he used with or without the usual fixed signals, depending upon the type of train control apparatus; and l have illustrated such fixed signals S conventioiially; Without attempting to illustratrotheir well known control circuits and devices".

lfhe truclmey element T of my invention in general comprises a magnetic yoke or core and associated coils, and is adapted to iuonoe by electromagnetic induction a cooperating element on it passing vehicle. In the construction illustrated, the trackway element T compriscs'a U-shuped core or yoke 5 provided with pole pieces 6, and

having coils 7 on its legs whichsre either oppositely w und 0f in the direction. with different number of turns. These trackwey elements 'l are intended to transmit; controlling influences or impulses tov a passing tmin stone or more control points in each. block; in accordance with trelfic conditions the next hlnck in' advance, or also in the corresponding block, depending upon the type of train control apparatus employed. in the treeliw'ey equipment shown vin Fig. i, a trot-laws) element '1 is located at the entrance to each block, a short distence in the rear of the insulated joints 2, the normal direction of tmilic being from left to right, as indicated by the arrow. The coils 7 of such ti'acltway element T are connected in series in it normally closed circuit including the front conteot oii a, line relayfi; in the arrangement illustrated, the controlling circuit for the lino relay 8 includes a front contact of the tits cl; relay 4 of the corresponding block and. a, front contact of the track relay 4 of the next block in advance, that the coils '2' of the truckwziy element 'l at the entrance to cosh block are in closed circuit under clear tmtli c conditions, hut are open-circuhn'l when eithcrthe corresponding lilo-cl; or the next'hlock in advance is occupied T treckway elements '1 may be located crosswise of the track hotu'oen the trecl: mils (ssshown in l), or lengthwise, 0?. outside of either truck mil, as pi'efei'retl. l'fiiclcr in practice to have the upper fat.- 'Lof the pole pieces 6 of the trucliway siertsiht 'l asxhigh as clearances on the po -similar railroad equipped will permit; and in some instances l consider it tii itl )lfi tolocute the tmcltway elements outside of the track mils, since there is ru vertical cleorsnce space oirtlmmi hie outside of truck sells it. should understoo meuts wmiiifljl li'ilihfi ftom the essential features of my invention.

The car-curried 01 engine element l1 Comprises in general a magnetic yoke or core Y ha'ing three legs 9, l0 and 11, each provided with the usual pole pieces, and each. havingsa coil thereon, as the coils 12, 13 and 1-1 respectively. It may be exluiuetl here that the distance between the egs 9--1()1l, and also the other dimensions of the yoke Y should'be modified in practice to provide the most ellicient'urrengement.

Obviously, the cross-section of.

the logs and their back yolies is preferably 7 made. as small as the flux density will permit so as to keep down the size and weight of the yoke Y. Also, the distance between the legs should preferably be as shorta's possible, the limitation being that the greater part of the flux should tend to pass down hrough through the two intervening air-gaps, rather than leak from the leg 9 to the log: 10. Thus, .while the track clement shown in Fig. l is nearly as wide the track gauge, the distance between the outside legs 9 and ii of the cur element may he made less than the truck gauge in most cases, and the track element is then located at one side of the center line of the track so to come under the less 9 and ill. The coils 3 and 14 on two oi the legs 10 and 11 are conveniently termed the secondary or receiving coils The soil 13 is theactiye or: working secondary co l, and the 001i M is the balancing or neutralizing secondary coil. These coils 13 and 14 are wound oppositely with substantially the some hum her of turns. The relative direction in which the turns of thesecoils 13 and 1% actually pass around the legs 10 and 11, starting from the same end, imziy he the some or opposite, depending on how these coils are connected together, that is, end to end, 01 beginning to .end. In any case, howevor the coils 13 and-l4 are so wound and connected together that the electromotive forces induced" therein by a change in the flux from the field coil 12 passing through the legs 10 and 11 in the same direction, either upor down, will oppose. eat-h other; audit is this arrangement which is understood by the use of the expression oppositely wound. The other coil 12 is preferably wound oppositely to the coil 13, or in the same direction with u. (liilerent number of turns. element. ii is supported in any suitable inuntoer from the frame of the locomotive or other vehicle, and is preferably nonadjustzihly secured. thereto in such a posi tion that its pole pwces 12 and 13 pass directly over polo pieces 6 oi, hctz'aclc element T, shown in Fig.5.. 2. In connection with. y employ an amplifying the track element,-

The cnginc and, detecting relay of the therinionic or vacuum bulb type, commonly known as an audionfi This audion, being 'Well known,

-has been illustrated "conventionally, and

' a battery A. The grid circuit includes in series the two secondary coils13 and 14 and a battery C. The plate. circuit includes a control relay R and batteries 13 and C. The control relay R is preferably a tractive relay provided with a large number of turns so as to be operable on small currents, and with a=lan2inated core, so as to be quickmcting. Y

The control l relay B may govern the op eration'ofany suitable form of train control-apparatus or device. Since the particular type of train control apparatus forms no part ofjnv invention, I have illustrated such deviceconventionally as an electropneunuitic valve, which may want the train pipe, and apply the brakes directly, or govern the operation of any other suitablegt'orin of train control means device K is normally energized when the control relay R- .is picked up and is decncrgized when the said control. relay drops. The coil 12', conveniently termed the field coil, is normally. energized by iurrcnt dcrivcd from the three batteries A, B and (I. For the-purpose of checking the integrity of this energizing circuit :for the field coil 12, said circuit is taken through the train control device K, the complete circuit beingz commencing at battery A, wire 15, coil 12, wire 16, train control device K, wires 17 and 18, front contact 19 of relay li, wires 20' and 21 to batten- B. A non-inductive resistance 22 is preferably connected across the front contact 19 at the relay B, so as to reduce the arcing of-t his contact whenflit opens, this resistance 22 being, of course, large enough so that the train control device K will not be hcld up if the front contact 19 is open.

, Normally, \vhilcthe car-carried clement L is'not passing over a track clement T, the control relay it is picked u p, and the (rain control device K energized; The voltages -ot'the batteries A, ii and C (which are really three sections of a single battery), to gether with the windings of the coils 12, 13, 15 and the various other parts, are so dc-- si'gned and!proportionedthat normally sufiicieut curient flows in the plate circuit through the control rclay R to maintain its front Cent- '01 1!) closed. The voltages of the batteries l and? (.1 will, of course, vary in practiddiilaccording to the type and opcrating cha jactcristics of the audion, and

,likewise thqnuinhcr of turns and resistance i1 of, the coils'12, 13 and 14, and the winding ofith e ooritcol riflay and the ftrain control The train control.

circuit, it is found that a change or 1 clement, it is cvident that Ont hi device K, will vary uudcr difi'crcnt conditions, depend o upon the electrical and magnetic charactcristics of the track and car-carried element, the air gap, and other factors. One typical. arrangement, which I have found satisfactory in practice, consists of battery A, four volts, battery B, 12 volts, battery C, 8 volts. lVith such an arrangcment of batteries, and an audion of the type.

commonlyconstructed, I use 3000 turns for the field coil 12. and 18,000 turns for the secondary coils 1?, and 14. one type of the control relay ll, which 'I have found satisfactoryin practii'c consists of a comparatively large nuinbcr of turns, for example,

72,000 turns. "he train control device K preferably lncludcs an .clcctroniagnct or solenoid liavi 11g the usual pickup and drop-- away characteristics. lt should be understood, however. that ihcsc. specific details of construction abovc mentioned are .susceptible of considi-nable variation in'practicc.

The operation is .as follows:lhidor clcar,traflic conditions, the coils T of the track element T are in a closed circuit of low resistance and when the engine clement L passes ()VOl this truck element, the car equipment is not influenced sufiiciently to operate the coi'itrohrclay ll. l attribute this to-thc action of the coils T which beingin a'closcd circuit, oppose or choke hack the passage of illlX through the yoke 5 of the track element '1, thereby preventing the change of flux in the yoke Y of the engine clcnicut L which occurs under. dangerous tialiic conditions to be now "described.

Under dangerous trafiic conditions, thocoils 7 of the track element T are opc.n-circuited, so that this track element prcscnis.

in 0 Feet a dead magnetic loop for the two legs 9 and 10 of the yoke Y and theirconnccting portion. Thus, as the yoke Y passes over thc track element T, the rcluctance of the magnetic circuit through thecoils 12 and -13,is.changed, and the flux and through said coil 13; but whether due 'to such diversion of'leakage flux: or; to a change in the reluctance of the map'uetic through the coil 12-3 actually occurs. Such a change in iiux through the coil 13 acts, in accordance with wcl known principles. to induce an Mfl in this coil! While this induccd l). M. F. is thoorctialluia complete alternating cycle, changing dir "on as the car clcincnt approachcsand leader.

halves of the wave of this induced M. F,

ill.

opposes the battery (l, and thus lowers the ootcntiul of the f Il l (It with respect to the phlfillllzlfil the n five end of the filament This likewise reduces the current normally flowing through the plate circuit, due to the \x'r-ll known" operating characteristics olltlie :nulion; an the parts are so proportioned that said current is thus reduced belowthe holdup value of the control relay ll. Thus, the front contact 19 of the relay ll opens, thereby causing the train control device K to operate. As soon as the engine element L pnsses'licyond the influence of the track element'l, the normal conditions are reestablished, so'tlmt the parts may be restored to theirnormsl condition, ready for the next operation. In this connection, stick circuits and manually or automatic operated. reset devices may be employedit desired; but since the particulsr manner in which the stoppingimpulse, after once received, i utilized to control the tsoin, forms no part of the present invention, the details of this control have not been shown.-

'Qne important requisite of twin control systemsfisthst fe-ilure at any of the essenti'al ports likely to brook down in genetics, should be upon" the side of This principle carried out ini'ny can. ment; The tics-in contt ol device itself is included in s notn nlly closed circuit, so that any interruption of this circuit, on failure of the better therein, results in this device being operated 4 Likewise, burning out of the filament I or any interruption in the grid or pietecircuits causes the relay R to open. Theitrein control device K, being inhided in the circuit for normally energizing the field coil 12, will be operated if the circult, is broken. In short, I have provided un interlinked series of normally closed or normally ener'gized eircuits,'the failure of any one of which results in the operation of the item control device, so that any failure of the equipment or circuit connections likely to occur in practice will be upon the sideof ssfelyf I From the preceding explanation it will be observed that the operation of the relay R is dependent upon the E. M. F. induced in the Working secondary coil 13. This in duced E. M, illin turn'depends upon the air gzup between the engine element L and the truck clement T, and the magneto-motive force protl'ucedby the current in the field coil 12. This moment in the field coil 12 de-- pends upon he battery voltage, and upon the resistance 'of this coil which varies according to its temperature. Furthermore, nth the some value of E. M. F. induced in the secondary coil 13, the margin 'for the operation otthe control relnv R depends J 1 1 a pen new moon tnis induced E. M. F reqlne s the curcent'tlien flowing through said ll, tootsie, upon the temperature'of the relsy tions exist.

essence filament F, and the amount of current-in the plate circuit. Therefore, in the part-mule type of system shown and described, generully speaking, the worst conditions for safe 0 oration, thst is, the least sensitiveness 0 the car equipment, consist of :1 long nix-gap, high filament temperature, high con minimum to 4 maximum, the engine ele: inent 'L being assumed-t0 be permanently and non-adjustably connected to the, engine 'frame- This minimum airgap existswhen the wheels of the car are worn down to their smallest diameter, and the maximumsirgep when new wheels are substituted; for worn wheels. These limltswill, of course, vary somewhat in practice, depending upon the road clearances and the extent to which the wheels are allowed to wear down. The bot-- tery voltage will van-v from maximum of npproximotelv 2.2 volts per cell, correspondmg to a full charge, to 1.8 volts per cell, corrcspondingto full discharge, assuming that a storage battery of the common type is used. The temperature of the field coil 12 will very approximately in accordance with variations in the atmospheric temperature,

which in tum will vary considerably depehding upon the location of the railroad.

\Vith the maximum variation of the feta tors above noted,-it has been found wither diflicult to select, an. equipment which, without some :idjustment, will be sensitive enough to operate undo: the worst conditions, and yet will notbetoo sensitive" to be improperly operated by the track rails at crossings and the like, when the best condi- My improved system obviates this objectlon by minimizing the effect of track rails and similar messes of iron along the track.

This action is doe to the additional leg 11 and the balancing or neutralizing secondary coil I l-thereon. L passesover, the track mils at zns'uhstant-ialIy right angled crossing, the resultant change of flux is substantially the some in both the legs 10 and 11, and the E. Ml l ind'wrw' 'l in the coil 13 is approximately balanced by the opposing E. M. F. induced in the coils 14. This balancing or neutralizing action is most eilective when the sevcral pole pieces of the engine element L pass simultaneously over a body of lion, like the track rail of a right angle crossing, and this condition is likewise the one having Villa-lithe engine element nlained thief-principles essence operation of the control relay R. In passing over switches, or rails making an acute angle with 'the track rails and the like, the coils 13 and 14 are successively influenced, so that'thc balancing effect is reduced, but these successive influences are suiiicient'ly simultaneous to cause them to oppose each other to a certain extent, and further the influences produced by such angularlydisposed rails are of a smaller magnitude than those caused by crossing rails at right angles to the trackway, because the aingap between such rails and the car element is much larger when these t we devices are angularly disposed with respect to each other,

- so that the tendency for a false operation is correspondingly 'reduced. Thus, the

provision of an extra leg 11 and the neutraL izing secondary coil 14 takes care of practically' all of the bodies of iron likely to be encountered along a. railroad track; and

in'case a body of iron influencing only the two coils l2 and 13 should exist, it is merely necessary to build out an extension at the 5 side otsuch a body to influence the neutralizing coil 14.

From the foregoing description it will be observed that the car element constitutes in effect two partial magnetic circuits in multiplewith the field coil 12, as a source of magneto-motive-force for said partial circuits. One of these partial magnetic circuits is through the legs 9 and 10, and the other through the legs 9iand 11. The track element T provides another partial magnctic circuit on the track cooperating or matching with the one on the car through the legs 9 and 10, and thus, when in the active stop-ping condition, completes the partial magnetic circuit on the car through the working, secondary coil 13,'thereby producing a change of flux therein and causlng operation of the relay- R in the/manner described. It will be evident that a track rail of a crossing, cross-over or the like, since it extends cross-wise of the running rails farther than the'track element, will complete both of the partial magnetic c1rcuits on the car.

The modified car equipment shown in Fig.8 isthe same as that shown in Fig. 2, exceptithat the field coil 12 is put upon the middli leg 10 of the yoke Y, and the two secondary coils 13 and {1.4 on the two outer D and ll of said yoke. This farrange- 'ment as the adyantage that the partial magiiidtic circuits on the car through the ldoil's l3 and 141318 substantially the' saintv ,flength, 0 saidinoils-lfi and 14 by zttrack rail more equal lfyi o/ppose each other.)

In escribing my invention, I have outlined certain specific constructions of the careduip lnlent and trackequipment, and exand mode of operso that the-E. M: F. induced in ation thereof; but it should be undemdod that these constructions do nctcrhaust all of the various embodiments of my invention. It isevi dcnt that various types of engine elements and trackway elements n'iay .be used, providing these elements cooperate to produce an induced voltage in a coil on the car by electromagnetic induction when it is desired to transmit a stopping impulse,

and further that this induced voltage is pro-' duced by the presence of a magnetic body along the track. 7

In order to explain the nature and mode of operation of my present invention, I have shown and described the devices and circuits of a complete system which are disclosed in generic and specific forms in other applications; and I desire to have it understood that my idea of the features of the system herein disclosed and not claimed form the subject-matter of other co-pending applications.

Various modifications and adaptations of the audion and its connections, other than the one illustrated, may be employed; and two or more audions, coupledin cascade may be employed, if desired. Likewise various combinations of battery or other sources of'current may be used, providing the appropriate potentials upon the filament, grid and plate of the audion are ob tained. In short, the particular constructions illustrated are susceptible of considei' able adaptation. and modification, and I desire to have it understood, therefore, that these specific embodiments of my invention shown and described are merely illustrations of the idea of means and the functions thereof constituting my invention.

\Vhat I claim as new and desire to secure by Letters Patent of the United States, 1s:

1. In an automatic train controlsystem, the combination with a track elementconstituting a partial magnetic circuit when in the stopping condition, of an engine element comprising a three-legged yoke, oppositely wound coils on two legs of said yoke and connected in series, both of said coils being subjected to substantially the same influence when the engine element passes an, ex-

traneous magnetic body along the track,

only one COll being under the influence of the regular track clenients,. electro-responsive means on the engine connected to said coils. and a normally energized-coil on the third leg.

Q. In an automatic train control system, the combination with a track element constituting a partial magnetic circuit whenv in comprising a threedegged yoke, a normally energized field coil on one leg of said yoke, other oppositely wound coils on the other two legs, said field coil and only one of said the stopping condition, of an engine element other coils being subject to the influence oil Mild track clement and clectro-rcs iorisive .mcansi having an operating circuit con- I nectctl to Fflltl oppositely wound coils in train control system,

having legs; a normally energized field coilon one leg: ail-electrically operable brake control device; a circuit including in Series a source of current, said field coil and said broke control device; a secondary coil on a leg of said'carwarriccl yoke; anti an electrores onsivetlerice intlncncccl by the M. F. inaucerl in the secondary coil ior controlling said brake control device.

5. In an automatic train control system, the combination with a controli'elay on a vehicle, of a thrce-leggcd enginc element and track clement adapted to cooperate through an intervening airgap varying from approximately 2 to al inchcs for controlling,

said relay, and 11182.39 associated with said engine element or preventing: operation of the control relay by the track rails at a crossing or the like at any of sairl airgaps.

' l; lo a. trainjcontrol atcnh the combinaticn svitha traclrwa'y cleric-e a cor-carried means adeptetljto coopcratcwith said trackway rlevicc, sairi means comprising afiux mdncing coil, an influence receiving coil magnetically coupled with sairl 'liux pro- (lacing coil, :1 control rclay having normallyicloserl contacts and connected to he responsive to the voltage induced in said influence receiving; coil, a normally energized train control device", a source of energy. and it normall}; energized circuit for saitl flux protluc-i ing coil including in caries eairl source. the contacts of said relafv and said device.

7-. In a system of tram control in Wlflflll ontrolling influences are produced by a change of reluctance ot a magnetic circuit.

of c ear-carried means caused by its passage over a trackway meanal said car-carried means comprising a. flax producing coil and an influence receiving COll having ts stopping operation dependent .on the energizetionof said flux producing coil; a normally energized electro resnonsive device adaotccl when dccnergizerl to cause rcterclation o the icaccoe through the brake-setting car; a, source of current; and a cir uit-inchuling in series said source, said flux producing coil and said device and governecl hy voltage changes in said receiving coil.

lo a system of train control in which controlling impulses are produced hya magnetic. cooperation lwtn'ec-n car-carried int-ans anti traclrway means, cancariietl means comprisin a flux producing coil and having its operation dependent on the encrgizaiion: of said coil; an clectro-rcsponsire device controlled by saichcancarriecl means and operable upon a predetermined decrease in the currentjlowingtherein to cause rctarclaticn of the car; said car'carrietl means 93%: including; a normally energized. control relay having normally closed contacts; a source of currcnt: and an energizing circuit for said flux producing coil including sairl device and the contacts or" said relayf i 9. (far apparatus for an automatic train control system). comprising a control relay having nrgmally closed contacts, aacleclarr rally operable train control device having an energizing circuit governed by said con- W tacts, and a shunt around said contacts hav' ing a resistance high enough to limit the flow of current through said clevice-hclon' the nine required to operate it.

10. In an automatic train control system. l5 car equipment comprising a control relay. an electrically operable brake-setting ap plianr-c, a normally energized coil for pro- (lir'ing fin a to govern the operation of the control relay. an energizing circuit, lllfilfifl- 1853 inglr sairl coil. the brake control (lOYlCQ and a front contact ohmic relay. and a shunt around the relay cont-act having a resistance high enough to limit the flow of cnrrenr appliance below 105 its operating value. 1 1l. ln'an automatic train control system. the combination with av tsain control iii-cane on a vehiclc. of an anr'iion ontrollingr said means. a normally energized circuit govern- 111i ingz said audinnl and means responsive t magnetic oodles extending partway acros the track but not all'of the way for producing a counter clcctro-motiveiorcc in said circuit. I

12. in. a system for lmnemittin; controlling: impulses 'l'roz-n thc track to moving vcliiclcs of tl'icitjs'pe in which a com-cc oi this: is mrrieil on the vehicle and ingxhih the track elements act when in the stopping: condition to complctc a partial magnetic circuit on the car including said source oi flux, the combination with sai l partial magnetic circuit. of means including an anclion and responding to a. change of flux in caitl circuit, and other means influenced by track rails extencling crosmeise of the running I rails ior preventing active response of mid filfiifilflfiii means to sairl track rcila. re train control cystin ma lrol apparatus on a vehiele,'a-relay governing said apparatus, an audion controlling the relay, a circuit normally maintaining a potential on the grid of the audion, tWo' oppositely wound coils included 'in said circuit, and means partly on the track and partly on the car for causing a change of flux in one of said coils but not the other under dangerous traffic conditions, said change in flux inducing a counter electromotive-force reducing the grid potential and 7 plate circuit of the audion.

15. Car equipment for automatic train control systems comprising train control ap-.

paratus, an an .ion, a normally energized con trol relay for governing said apparatus and included in the plate circuit for the audion, and two coils and a core therefor constituting a partial magnetic circuit on the car, said coils being wound and connected; together in the grid circuit of the audion so that: a change of flu);- passing through said coils in the same direct-ion induce opposing elcctro-1notiveforces. i i

16. In a train controlsystem, car equipment comprising train control apparal'usba relay for controlling saidapparatus, an impulse element comprising a back yoke having three legs, a normally energized coilon one leg teomg to send flux in the same direction im .tahother legs, a source of cur rent and a circuit for energizing said coil,v

oppositely wound coils on the other two legs, another circuit for controlling the relay including said oppositely wound coils in Se rics, a track element comprising aimagnetic core spanning two legs of said eJ t'ment and having a winding for opposing the passage of flux through the core, and tratlic controlled means for opening and clo .ga circuit of low resistance through said winding.

17. In an. automatic train control system, a car equipment comprising athree-legged yoke carried on the car crosswise thereof, train control apparatus, an, electro-responsire device governing said apparatusf an. energized field coil, on one leg ot'isaid yoke, separate secondary coils on'the other legs, both capable of influencing said electro-responsive device,v said device being operated when flux from the field coil through one 'but not both of the secondary coils is changed and trafiic controlled track elements acting when in the active'stoping condition to cause a cliangeof' fins through one but not both of said secondary coils.

.18. In an aut omaticutrain control system the combination on ayehicle, of means for, governing theopersi-t'idn of, said vehicle by apparatus inductively by afield of'flux between the rehiclc and track, said means comprising acar-carried elemeutihaving a yoke provided with only three legs, a none;

mally energized field coil on one leg,- o

secondary coil on another leg, a track element adapted to provide a partial magnetic circuit between the leg carrying the fieldcoil and the leg carr ying the secondary coil,- tratlicontrolled means for opposing the passage of flux throngh thetrack element 7 under clear traflic conditions, and means .associated'with the third leg for preventing. operation of the train control apparatus,

said last mentioned means being operable when part al magnetic circuits on the track are established between the leg carrying the tield coil and hoth'of the other two legs.

19. Car equipment for automatic train trolling impulses are communicated by magnetc cooperation betwee'rrdevices on,

control systems, of the type in which con?- the trackway and devices on the yehiclesi.

moving thereon, comprising 'a; three-legged element having oppositely Wound coils on two of I coils in seres, andautomatic train control its legs, a circuit connecting" said;v

means'respdnsive toa change in the current i in said circuit.

20. (ar equipment for automatic "traincontrol systems,- of the type in which controlling impulses arev communicated by magnetic cooperation,between: devices on I the traekway and devices on the veh-icles' moving thereon; comprising a three-legged element; a normally energlgc'dE-fieldcoil on the middle leg. oppositely Woimdgsecondary coils on the other two legsf andtra'in con: trol means governed acting in series. i 1

21. In an automatic train control'system,

the. combination with a U-shaped track e ment, of athree-legged car element having two of its legs spaced apart 'suliif itantially the same distance as the legs of'the track element, and having a magnet zing 'coil on one of said legs. said spacing beinggreater than twice the air-gap between tll'dtl'W-lt element and tluycar element. means outlying thepartial ma netic circuit on the -'car formed by said two legs-of the car element and completed bythe track element for 0011- trolling the car, and mean esponsiveft-o bodies of magnetic inmate crosswise of-thetrack a greater "distance that the spa-cebetweenthe legs of track I element for preventing operation of sai'd meansw V 22. -In an e ema trainicontrol system of the; type in which a source. of.--magnetoby the secondary coils l extending I 529 apparatus.

which the track elements act when in the stopping condition to complete a'p'artial,

magnetic circuit on the vehicle including said so urce,"'the combination trainecontroi meanson the car, of means including a thermionic 'relay and responsive to, said track. elements but notto'rails extending" crosswise of the track for controlling said 23. In a system of train control in which controlling influences are produced by a change of reluctance of a car-carried partial magnetic circuit m cludmg a' flux producing-coil, means magnetically coupled with. said flux producing coil including a control relay, a normally. energized electroresponsive device adapted when deenergized 'tocause a retardatlon of the car, a

series said source, said coiland said detice. and governedby said control relay.

24. In a system of train control in which controlling influences are produced by a change offlux in a car-carried means by a trafiic controlled trackway means, said carcarried means comprising a flux producing coil. a train control devi e. a normally energized circuit magnetically coupled with said coil and adapted when deenergized to trolrelay having normally closed contacts actuate said train control device; a source of current; and a circuit including in series said source, said coil and said device, and governed by the car-carried means.

25. In'a train control system in which influences are transmitted from the trackway to the vehicle inductively; car-carried apparatus comprising a flux producing coil, an influence rmeiving coil" magnetically coupled to 'saidflux producing coil, a control relay in circuit with said influence re ceiving coil; trackway means comprising an inert'hody of magnetic material adapted to transmit an influence from said flux producing coil to said receiving coil when passing tliereover; a train control deviceya source of energy; and a circuit including in series said source. flux producing coil and train control device. and

relay. 26. Car-carried apparatus for-train con trol systems comprising, a flux producing ijcoil, an influence receiving coil magnetically gl coupled with'said flux producing coil, a con- ;ld connected in circuit'with said receiving mflg'agnormally' energized train control dea source of energy, and'a normally circuit for said fiuxproducing coil incinding in series said source, the con 'tajetmofisaid relay and said device.

governed by said con- Y -1ng coll including in series said sour e. the

27. A train *eontrol s stem, as specified in claim. 26, having a discharge resistance shunted across the conta t of llH (rzLU'nl relay.

28. In a train control system. the combination of a trackway divided into blocks in insulating joints; each block having a track circuit provided ivith a track relay and a source of energy: means at the entrance of each hlock comprising a signal: and a truck element controlled by the track circuit of that block and the next block in advance: and a car-carried equipment comprising a three-legged element having oppositely wound coils on tu'o'of its legs and so disposed on the car that one of said two legs and the third leg come int conu'nxmir'nting relation with said track element as the car element passes thereover.

, 29. In a train control syst'cm.:the comhination of a trackway divided into blocks by insulatingzjoints; each block having a track circuit provided with a track relay and a source of energy. means at. the entrance of each block including a. track element and a signal. said track element being controlled hv aline relav controlled by the track circuit ofthat block and the track cirone of saidtvro legs and the third leg come into communicating relation with said track element as the car element passes thereover.

.30. In a train control system. the combination with a trah'ic controlled trachway element.. of car-carried means adapted to cooperate with said trackway element .said means comprising a flux producing coil. an influence receiving coil magnetically coupled with said "flux producing coil. a control relay having nonnally closed con 'tacts and. connected in circuit with said receivin'gcoil, a normally energized train control device, a source of'enern v. and a normally energized circuit for said flux produccontacts of'said relay and said device.

31. Influences communicating means for automatic train control systems comprising a three-legged element of magnetic mater'ial, coils on the outside legs of said element. a thermionic amplifier having a grid circuit including said coils. and electroresponsive means for controlling the train governed by said'thermionic amplifier.

- (messes. PAUL.

ioo 

